This blog provides updated forecasts and comments on current weather or other topics

Tuesday, February 10, 2009

Showtime

The major act of this play is now beginning. So far the models have done a splendid job. As predicted southeasterly flow developed, with downslope on the western slopes of the Cascades causing drying and upslope on the SW of Olympics forcing some moderate to heavy snow. Look at the radar...you can see the large gradient of precipitation and the heavy snow over the Kitsap. Shelton is reporting very heavy snow right now...and one of our correspondents has 4 " on the ground near the Hood Canal at 500 ft. And they are going to get a lot more.The main front is now making landfall (see high res satellite picture). As a result, precipitation intensities will increase over the interior of western Washington--and it has been snowing along the coast all morning from it. The big question is temperature...can they stay low enough to maintain the snow and for how long--since temperatures will be increasing aloft due to the warm front. Some insight into the temp structure aloft is available from the Seattle profiler (see image). When you look at the temperatures, subtract 1C...since it is showing something slightly different than temperature (virtual temperature). The freezing level has risen to about 400 meters (1300 ft), with a snow level of roughly 300 ft. But that will come down quickly when real precipitation starts. In fact, snow has already begun in earnest at Olympia (see image), with light snow spread to Sea Tac. Fortunately, the temps are above freezing and the roads are relatively warm...so the snow should not stick well on busy hiways.

Serious snow started about 45 minutes ago, snowing enough to stick and slush on roads now with about 1" accumulation on cars. Great big fluffy flakes, unlike earlier this morning when it was more like being in a snow-globe.

I just ran down to Silverdale. On the way my car thermometer read 37F. Light snow when I went into Costco. Coming out (and I wasn't there long) heavy snow. Car thermometer read 33F. The driving is starting to get interesting. Back here in Kingston, still just light snow and none is sticking.

Here at the University of Washington, it has been back and forth between snow and rain (and sometimes a mix of both) since 12:45ish....about 10 minutes into my run - fun! Nothing is sticking though, which makes for fun weather without the dangerous driving conditions....

Has been snowing on Union Hill just outside of Redmond (600') for about an hour and a half. Nothing really sticking yet. Maybe a little. We had a period of big, fluffy flakes. But now they are just tiny.

I reported in this morning at 11:40 with 4" of snow on the ground at 500 feet elevation just above Hood Canal near Union. At 4:25 we now have 7 1/2" and still a steady temp of 32--and at this point moderate snowfall.

I heard that the snow will taper off from the north to the south. If this is true, then will the Olympia area get any more snow tonight? I'm hoping for a two hour delay at least. As long as it freezes.

A quick look at the radar, and there are two things you can see, one clearly, the other not so clearly.

1) The snow/rain/whatever else you all are getting, looks to have its end just a little SW of Tacoma on I-5.

2) But it does look like that it is going to give us one last jot of snow or rain. It looks like to me, I'm not sure about you, but the precip. intensity is increasing a bit everywhere - especially around Everett. But also right below Seattle.

The area of low pressure off our coast looks very intense. Any idea if we are going to see any accumulation of rain/snow from this area of disturbed weather? It looks very ominous from satellite view..

Olalla: It started snowing in earnest around 11 this morning and we accumulated 2 to 3 inches, without the temperature ever going below freezing. We walked in the woods and it was quite a hike...we often had to shake the snow off little trees to get them out of the way...that much wet snow weighs quite a bit, and a lot of the trees were weakened already from the December snows. Finally around 3:30 to 4 it changed to rain. No pptn now - 9:30 - but many dripping sounds.

Hey Brian... I have seen the latest 00z operational GFS, and it does`nt look good for any wind storms or any snow events down here over the next 2 weeks or as far as the eye can see.

Here`s what I do see though..----------

Latest 00zGFS Shows that tomorrow and Thurs should be mainly dry, though cool as thicknesses are in the upper 520`s. Then for Fri, we get N-NW flow as a weakening system dives SWWRD from the GOA and heads to Oregon/California. However, this system will be passing close enough to our coast that we may end up seeing some showers over us for Fri and maybe into Sat as well. And for Sun, though with exception of maybe a few mountain showers, the interior lowlands looks dry with flow aloft at 500mb becoming more SSWLY during the morning hours on Sun. Should be a cool weekend though as thicknesses look to be in the mid-upper 520`s with 850mb temps between -3 and -6c. So could be a few isolated snow showers in the Cascades. For the Mon-Thus of next week, that looks a bit unsettled as the flow aloft looks kinda splitty, but also at the same time, a large and open surface/upper level trough looks to park it`s self not to far off the west coast. This trough looks to be a little showery at times with spotty showers over OR/WA along with 500mb heights near or at 540dm and low thicknesses in the 520`s. But we may also see some sun at times with this weak and splitty flow showing up for next week here in the latest GFS model.

Long term:The long range GFS from about late week onward shows our pattern to continue in bit of a unsettled fashion with coolish/wet troughy and or splitty type pattern. Pretty much a no go for a 'major cold' here in Western WA, but the mountains will be getting snow at times as usual.